Continuous and filter-based measurements of PM 2.5 nitrate and sulfate at the Fresno Supersite

Chow, JC; Watson, JG; Lowenthal, DH; Park, K; Doraiswamy, P; Bowers, K; Bode, R

HERO ID

835403

Reference Type

Journal Article

Year

2008

Language

English

PMID

17929182

HERO ID 835403
In Press No
Year 2008
Title Continuous and filter-based measurements of PM 2.5 nitrate and sulfate at the Fresno Supersite
Authors Chow, JC; Watson, JG; Lowenthal, DH; Park, K; Doraiswamy, P; Bowers, K; Bode, R
Journal Environmental Monitoring and Assessment
Volume 144
Issue 1-3
Page Numbers 179-189
Abstract PM(2.5) nitrate (NO-(3)) and sulfate (SO=(4)) were measured continuously with R&P8400N and R&P8400S instruments, respectively, and compared with filter-based measurements at the Fresno Supersite from October, 2000 through December, 2005. NO-(3) concentrations were higher in winter than summer with a long-term decreasing trend. Correlations between 24-h average continuous and filter-based NO-(3) were greater than 0.96 in 4 out of 5 years. Continuous NO-(3) was generally lower than filter-based NO-(3) although the difference decreased over time, from -52% in 2001 to +13% in 2005. These differences were similar in winter (-23%) and summer (-19%) while the corresponding differences between ambient and instrument temperature were -12 and 0.7 degrees C, respectively. Neither seasonal nor long-term trends in NO-(3) can be explained by variations in ambient temperature, the difference between ambient and instrument temperature, or changes in aerosol chemical composition. There were no seasonal or long-term trends in SO=(4) concentrations, partially due to low concentrations observed in Fresno. Long-term variability in the performance of R&P8400 NO-(3) and SO=(4) instruments suggest that collocation with filter measurements is needed for long-term measurements.
Doi 10.1007/s10661-007-9987-5
Pmid 17929182
Wosid WOS:000258781700017
Is Certified Translation No
Dupe Override No
Comments Source: Web of Science WOS:000258781700017
Is Public Yes
Language Text English
Keyword PM2.5; nitrate-sulfate; supersite
Is Qa No